Disposable electrode

ABSTRACT

A disposable electrode structure for operatively connecting electrical equipment to the surface of live skin of a patient, employing a self-contained electrical conductive material for affecting the connection, and cover means for protectively sealing said conductive material, readily removable from the electrode structure at time of use.

United States Patent 1191 Sessions Apr. 23, 1974 DISPOSABLE ELECTRODE[76] Inventor: Robert Sessions, German Church Rd., Hinsdale, ll].

[22] Filed: May 24, 1973 [21] Appl. No; 363,717

Related US. Application Data [63] Continuation of Ser. No. 175,443, Aug.27, 1971,

abandoned.

[52] US. Cl. l28/2.06 E, 29/629, 29/630 R, l28/2.1 E, 128/417, l28/DIG.4 [51] Int. Cl A6lb 5/04 [58] Field of Search l28/2.06 E, 2.1 E, 404,128/411, 417, 418, DIG. 4; 136/175; 29/629,

[5 6] References Cited UNITED STATES PATENTS 2,887,112 5/1959 Smith128/417 3,085,577 4/1963 Berman et al. 128/418 3,170,459 2/1965 Phippset al....

3,487,827 1 1970 Edmark 3,518,984 7 1970 Mason 3,581,736 6/1971 Zenkichl28/2.06 E

Primary Examiner-William E. Kamm Attorney, Agent, or Firm-l-lill,Sherman, Meroni,

, Gross & Simpson 57 ABSTRACT A disposable electrode structure foroperatively connecting electrical equipment to the surface of live skinof a patient, employing a self-contained electrical conductive materialfor affecting the connection, and cover means for protectively sealingsaid conductive material, readily removable from the electrode structureat time of use.

24 Claims, 4 Drawing Figures DISPOSABLE ELECTRODE BACKGROUND OF THEINVENTION With the development and common usage of various types ofelectrical and electronic equipment for measuring and/or monitoringhuman body functions and the like, the demand for a suitable, highly'efficient electrode structure has progressively increased.

While it has been demonstrated in the past that an electrode structureemploying a suitable conductive material such as a conductive gel, wouldappear to be the most effective from an operational standpoint, the useof such conductive gels has resulted in additional problems,particularly in connection with preserving the usefulness of the gelover prolonged periods whereby the electrode structure will have arelatively long shelf life, i.e., from manufacture to actual usage.

It has proved to be desirable to clean and slightly roughen skin surfaceat the point of connection of the electrode thereto.

Likewise, as reuse of a medical or surgical structure will normallyrequire cleaning, sterilization, etc., the utilization of a disposabletype structure requires not only a highly efficient structure but onethat is very inexpensive to manufacture and generally quite simple inconstruction.

SUMMARY OF THE INVENTION The present invention therefore has as itsprincipal object the production of a highly efficient electrodestructure of the type involved, utilizing a conductive gel or othersuitable material as the connecting medium and yet which is relativelysimple and relatively inexpensive to manufacture whereby the same may beeconomically employed as a single use structure which is disposablefollowing use.

This is accomplished in this invention by employing a structurecomprising a plurality of sheets of suitable material, certain of whichare each provided with a layer or coating of adhesive which form themeans for securing respective elements to one another permanently, ordetachably, and for connection of the structure to the skin of thepatient. The metallic electrical terminal is disposed for connection tosuch skin surface by means of a conduit in gel, carried on a paddisposed at such terminal.

The conductive gel is protected, prior to use by a cover assembly whichincludes an annular spacing member encircling the pad and gel, aprotective sheet for the skin-engageable adhesive, and a cover sheet,the assembly being cooperable with a portion of the electrode structureto form a sealed protective enclosure for the pad and gel, operative toprevent undesired deterioration thereof over relatively long periods ofstorage, etc., prior to usage.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings, wherein likereference characters indicate like or corresponding parts:

FIG. 1 is a transverse sectional view of a disposable electrodestructure and its protective cover assembly, taken approximately on theline II of FIG 2;

FIG. 2 is a bottom view of the structure as illustrated in FIG. 1;

FIG. 3 is a sectional view similar to FIG. 1 of the electrode structurefollowing removal of the protective cover assembly therefor; and

FIG. 4 is a plan diagrammatic view illustrating respective steps of amethod of making the electrode structure and its cover assembly.

DETAILED DESCRIPTION OF THE INVENTION Referring to FIG. 1, 2 and 3, thereference numeral 1 indicates generally the electrode structure inaccordance with the present invention while reference numeral 2indicates generally the protective cover assembly adapted to be engagedtherewith and subsequently stripped off at time of use. While otherconfigurations may be suitable in specific applications, I have foundthat in general a circular configuration is preferable and the variouscomponents making up the electrode structure and the basic coverassembly structure are illustrated as being circular in configurationwith the various components generally arranged on a common axis.

THE ELECTRODE STRUCTURE Referring to FIGS. 2 and 3, the electrodestructure 1 comprises a first sheet 3 of suitable material and generallycircular in configuration. I have found that'a thin fibrous porousmaterial is preferable. A very satisfactory material is that known asMicropore, a brand manufactured by Minnesota Mining & Mfg. Co. The sheet3 is provided with an opening 4 therein, likewise illustrated as beingof circular configuration, across which extends a second relativelyimpermeable sheet 5, likewise of circular configuration, of a size tocompletely cover the opening 4 and overlie the sheet 3 ad-' jacent theperiphery of the opening 4, the sheet 5 having a layer 6 thereon ofsuitable adhesive by means of which the sheet 5 is firmly attached tothe sheet 3. The sheet 5 preferably is fabricated from suitableplastics, a polyethylene-vinyl laminate being particularly suitable. Thesheet 3 likewise provided with an adhesive coating 7 on the lower orouter face as viewed in FIG. 3 by means of which the structure may besecured to the skin of a patient, theadhesive being of the nontoxic typecommercially procurable.

Secured to the second sheet 5 is an electrical terminal, indicatedgenerally by the numeral 8 which is illustratedas comprising an outerconnector-member 9 and an inner conact member 10. The connector member 9comprises a circular base portion 11 from which extends a hollow bulbousportion 12 while the inner member 10 comprises a similar circular baseportion 13 from which extends a hollow shank or stem 14. The latter isinserted in the bulbous portion 12 and the free end crimped over duringthe mounting operation to rigidly clamp the two members in operativeposition with the stem 14 extending through the sheet 5 and the latterfirmly secured between the base portions 11 and 13 of the respectivemembers. Disposed in the opening 4 and overlying the base portion 13 ofthe member 10 is a circular porous pad 15, secured in operative positionby means of the exposed adhesive on the sheet 5. The pad 15 may beconstructed, for example, of a porous or foam-type plastic such as thatused in plastic sponges and the like, the pad 15 having or containing asupply of a conductive gel 16.

As illustrated in FIG. 3, the bulbous portion 8 of the member 9 formsone half of a connector structure, to which another cooperable connectormember 17 may be engaged, whereby an electrical conductor or the like 18may be connected to the terminal 8.

In use, the electrode structure illustrated in FIG. 3 is applied aftersuitable cleaning or preparation, if any, of the skin surface, bypressing th structure down the the skin surface to bring the pad 15 infirm engagement with the skin surface, following which the peripheralportions of the structure are pressed firmly into engagement with theskin surface, whereby the adhesive layer 7 will firmly adhere to suchsurface and thereby effectively secure the electrode structure'thereto,with the pad 15 thus providing a good physical connection between thecontact member of the terminal 8 and the skin surface while the gel 16forms an efficient electrically conductive connection between such skinsurface and the base portion 13 of the member 10. Following suchmounting of the electrode structure, the connec-.

tor member 17 may be engaged with the terminal 8 to operatively connectthe conductor or line 18 to the electrode structure.

PROTECTIVE COVER ASSEMBLY The protective cover assembly 2 is constructedto not only seal the pad and the gel 16 carried thereby, as well asprotect the adhesive layer 7, but to prevent undesired contacting of thepad and thus possible squeezing forces on the pad, which might force thematerial 16 therefrom and thus possibly impair the operation of thestructure at the time of use. In the embodiment of the inventionillustrated, the cover assembly 2 cornprises a relatively impermeablesheet of material 19, preferably heavier and stiffer than the firstsheet 3 of the electrode structure, for example, a suitable paper, thesheet 19 having substantially the same external diameter as the sheet 3and provided with an opening 20 therein which, in the embodimentillustrated, is slightly smaller than the opening 4 in the sheet 3.

Disposed at the exterior face of the sheet 19 is a spacing ring 21 ofsuitable material, for example, polyethylene, the ring, as illustrated,having an inner diameter which is less than the diameters of bothopenings 20 and 4 in the respective sheets 19 and 3, whereby the innerface of the ring 21 may be engaged with the adhesive layer 6 on thesheet 5 to provide an effective seal between the latter and the ring. Atthe same time, the inner diameter of the ring 21 is greater than thediameter of the pad 5, whereby the ring will not engage and compress thepad. Overlying the ring 21 is a cover sheet 22, illustrated as having adiameter intermediate the outer diameter of the ring 21 and the outerperipheral edge of the sheet 19, the sheet 22 having an adhesive layer23 thereon by means of which the sheet is firmly secured to the adjacentface of the ring 21 and to the adjacent outer face of the sheet 19. Thesheet 22 preferably is adapted to provide an effective seal for the gel16 and conveniently may be fabricated from the same material as thesheet 5. Likewise, the sheet 22 preferably has a diameter sufficient topermit the effective engagement of the sheet 22 to the sheet 19 to forma unitary cover assembly. To provide further protection of this gel 16,a second pad 15', may be provided which is disposed in opposition to thepad 15 and secured to the cover assembly by the adhesive layer 23 as thesheet 22. This construction eliminates any possibility of the pad 15 andgel thereon coming in contact with the adhesive layer 23.

It will be particularly noted that the pads 15, 15' and the material 16contained thereon are, by this construction, effectively sealed againstexternal contamination with the ring 21 and sheets 5 and 22 forming asubstantially air-tight chamber in which the conductive material may bestored for relatively long periods of time without materialdeterioration.

When it is desired to use the electrode structure, the protective sheet19 is merely stripped from the sheet 3 carrying with it the spacing ring21 as well as the cover sheet 23 and pad 15. In this connection, it willbe noted that in the construction illustrated the ring 21 partiallyoverlies the sheet 19 so that the adhesive layer 6 on the sheet 5 is notin contact with the entire area of the adjacent face of the ring 21,whereas the opposite face of the ring is in contact throughout its areawith the adhesive of the cover sheet 22. In view thereof, as well as thefact that the ring is, in effect, partially gripped between the sheets19 and 22, the ring 21 will readily separate from the sheet 5 instead offrom the remainder of the cover assembly.

To facilitate such stripping, the sheet 19 preferably has a radiallyextending cut 24 therein extending from the opening 20 to the peripheryof the sheet to enable the sheet 19 to be readily grasped thereat forstripping.

Likewise, if the sheet 19 does not have a smooth surface readilystrippable from the adhesive 7, the sheet may be provided with suitablesurface coating, for example, a suitable silicone of known type. Acleaning strip 25, having a rough outer surface may be mounted on theface of the core assembly for use as an abrading type cleaning memberand may, for example, be formed from a synthetic rubber material.

MANUFACTURE OF THE STRUCTURE A preferred method of manufacture of thestructure above-described is illustrated in FIG. 4 which depictssuccessive steps in such manufacture with alternate steps II beingillustrated.

The first step, as illustrated at I, may be the forming of an opening 4in an adhesive coated strip of stock S from which the sheet 3 is to beeventually produced. The circular sheet 5, following cutting fromsuitable adhesive coated sheet stock is then disposed over the opening4, as illustrated at II, and pressed into firm contact therewith wherebythe adhesive coating on the sheet 5 will firmly secure the latter to thestrip S. The terminal 8 may then be applied to the sheet 5 in anysuitable manner in accordance with the techniques commonly employed inconnection with such type of structure.

If desired the terminal 8 may be first mounted on the sheet I and thenthe latter secured to the stock S'as illustrated at IIIT. IIIBillustrates the assembly at IIIT but from the reverse side of the stripS and at IV the previously formed sheet 19 with the cut 24 therein isdisposed in operative position and firmly mounted by means of theadhesive layer 7 to the strip S. At V this ring 21 is applied, engagingthe adhesive 6 of the sheet 5. At VI, the pad 15 is disposed inoperative position and firmly engaged with the adhesive layer 6. The pad5 is then impregnated with the conductive material 16 at VII, followedby the placement of the pad 15. If desired this gel may be disposed withthe pad 15.

The cover sheet 22, following previous formation from adhesive coatedstock is applied in operative position, as illustrated at Vlll, andfirmly adhesively connected with the adjacent face of the ring 21 andouter surface of the sheet 19, following which the cleaning strip isadhesively secured to the assembly, as illustrated at IX. The strip S isthen suitably cut to provide a circular configuration to the sheet 3, asillustrated at X, completing the manufacture.

In some cases it may be desirable to initially secure the pad with orwithout the gel 16 to the cover sheet 22 and then secure the cover sheetto the assembly.

It will be noted that the various production steps are each simple inthemselves and as the adhesive coatings enable fast and effectiveconnection between the respective parts, assembly may be performed at avery rapid rate.

It will be particularly noted that the enclosure of the pad 15 and itscontents of conductive material by the pad 15', polyethylene ring 21,and sealed by the respective polyethylene-vinyl laminated sheets 5 and22, insure an air-tight sealing of the conductive material whereby thesame may be stored over relatively long periods without materialdeterioration.

The inclusion of the cleaning strip 25, while not directly required withan electrode structure, enables the operator to quickly and effectivelyprepare the skin surface prior to the mounting of the electrode withoutother apparatus and at the same time provides an individual cleaningmember for each electrode.

Having thus described my invention it will be obvious that variousimmaterial modifications may be madein the same without departing fromthe spirit of my invention.

I claim as my invention:

1. A disposable type electrode for operatively connecting electricalequipment to the surface of live skin of a patient, comprising a sheetof relatively porous material having an adhesive coating on one facethereof adapted to adhere to such a skin surface, said sheet having anopening therein, a second sheet of relatively impermeable materialcompletely spanning the area of said opening, said second sheet havingan adhesive coating on the adjacent face thereof contacting said firstsheet for retaining the same in assembled relation an electricalterminal extending-through and secured to said second sheet on a portionthereof extending across the opening in said first sheet, said terminalhav-' ing means at the outer side of said second sheet for effectingconnection with an electrical conductor, and having a contact portiondisposed in the opening said first sheet, the area of said opening beinggreater than the area of said contact portion to provide an annular areatherearound at which the adhesive coating of said second sheet isexposed, a pad of porous material disposed at the opening in said firstsheet and engaged with said contact portion, said pad having an areagreater than that of said contact portion and retained in operativeposition in engagement therewith by the exposed adhesive coating of saidsecond sheet, and a quantity of electrically conductive materialcontained on said pad, preapplied thereto and forming therewith aunitary part of the electrode, operative to produce 'a conductiveconnection between said connector and live skin in contact with said padwhen said first sheet is applied to such live skin and retained inposition by the adhesive coating of such sheet. on a portion thereofextending across the opening in said first sheet, said terminal havingmeans at the outer side of said second sheet for effecting connectionwith an electrical conductor, and having a contact portion disposed inthe opening said first sheet, the area of said opening being greaterthan the area of said contact portion to provide an annular areatherearound at: which the adhesive coating of said second sheet isexposed, a pad of porous material disposed at the opening in said firstsheet and engaged with said contact portion, said pad having an areagreater than that of said contact portion and retained in operativeposition in engagement therewith by the exposed adhesive coating of saidsecond sheet, and a quantity of electrically conductive materialcontained on said pad, preapplied thereto and forming therewith aunitary part of the electrode, operative to produce a conductiveconnection between said connector and live skin in contact with said padwhen said first sheet is applied to such live skin and retained inposition by the adhesive coating of such sheet.

2. An electrode according to claim 1, wherein the dimensions of theopening in said first sheet of the electrode structure are greater thanthe corresponding outer dimensions of said pad to provide an annularspace between said pad and first sheet at which the adhesive coating onsaid second sheet is exposed, and clo sure means in sealing engagementwith said second sheet.

3. An electrode according to claim 1 wherein said pad, respective sheetsand 'the opening in said first sheet are respectively circular inconfiguration, with the respective components and said terminal beingdisposed on a common axis.

4. An electrode according to claim 1, wherein said electrical terminalcomprises an outer connector member and an inner contact member engagedtherewith, each of which is provided with a base portion in contact withthe adjacent face of said second sheet, that of the inner member beingin engagement with the adhesive coating on said second sheet, said innermember extendingthrough said second sheet and engaging said outer memberwith said second sheet clamped between said base portions.

5. As an article of manufacture, a disposable type electrode foroperatively connecting electrical equipment to the surface of live skinof a patient, comprising a sheet of material having an adhesive coatingon one face thereof adapted to adhere to such a skin surface, said sheethaving an opening therein, a second sheet of material completelyspanning the area of said opening with its peripheral portionsadhesively secured to said first sheet to retain the same in assembledrelation, an electrical terminal extending through and secured to saidsecond sheet on a portion thereof extending across the opening in saidfirst sheet, said terminal having means at the outer side of secondsheet for effecting connection with an electrical conductor, and havinga contact portion, disposed in the opening in said first sheet, a pad ofporous material disposed at the opening in said first sheet and engagedwith the adjacent contact portion, said pad being retained in positionby adhesive surrounding said adjacent contact portion, a quantity ofelectrically conductive material contained on said pad operative toproduce a conductive connection between said connector and live skin incontact with said pad when said first sheet is applied to such live skinand retained in position by the adhesive coating of said sheet, and aprotective cover structure for said pad and exposed adhesive of saidfirst sheet, of a size to extend across and engage said adhesive of thefirst sheet, the adhesive-engaged surface of said cover structure beingsuch that the latter may be easily stripped from such adhesive, saidcover structure having means for spacing the portion of said coverstructure covering said pad, outwardly from peripheral portions of saidcover structure, forming a recess at the inner side thereof, into whichsaid pad extends.

6. An article of manufacture according to claim 5, wherein said coverstructure comprises a protective sheet engaged with the adhesive of thesaid first sheet, and having an opening therein greater in size thansaid pad, an annular spacing member encircling the opening in such sheetand having an internal size greater than that of said pad and anexternal size greater than the opening in such protective sheet, and acover sheet greater in size than said spacing member overlying thelatter and having a coating of adhesive on the adjacent face inengagement with said spacing member, the peripheral edges of said coversheet extending laterally outward from said spacing member and inadhesive engagement with the outer face of the adjacent sheet of saidcover member.

7. An article of manufacture according to claim 6, wherein said sheet ofthe cover assembly contacting the adhesive of said first sheet isprovided with a cut therein extending from the opening therein to theperiphery thereof for facilitating stripping of such sheet from saidfirst sheet and thereby the cover assembly from the electrode structure.

8. An article of manufacture according to claim 7, wherein the surfaceof said sheet of the cover assembly contacting the adhesive of saidfirst sheet is provided with a coating of a material which will permitrelatively easy stripping of said sheet from the first sheet.

9. An article of manufacture according. to claim 8, wherein said surfacecoating comprises a silicone composition.

10. An article of manufacture according to claim 7, wherein said pad,spacing member, respective sheets and the openings therein arerespectively circular in configuration, with the respective componentsand said terminal being disposed on a common axis.

11. An article of manufacture according to claim 6, wherein thedimensions of the respective openings in said first sheet of theelectrode structure and said protective sheet are greater than thecorresponding inner dimensions of said spacing ring, whereby said padand its contents are sealed by said ring, the second sheet of theelectrode structure and said cover sheet of the cover assembly, saidsheets being secured to said ring by the respective adhesive coatings.

12. An article of manufacture according to claim 6, wherein saidelectrical terminal comprises an outer connector member and an innercontact member engaged therewith, each of which is provided with a baseportion in contact with the adjacent face of said second sheet, that ofthe inner member being in engagement with the adhesive coating on saidsecond sheet, said inner member extending through said second sheet andengaging said outer member with said second sheet clamped between saidbase portions.

13. An article of manufacture according to claim 5, comprising a path ofmaterial secured to said cover assembly and having a relatively roughexterior surface which may be employed to roughen the skin surface ofthe patient at the point of application of the electrode thereto.

14. An article of manufacture according to claim 13, wherein said patchcomprises a strip of adhesive backed synthetic rubber or the likeadhesively secured to said cover assembly.

15. An article of manufacture according to claim 5, wherein said coverassembly is provided with a porous pad disposed within said annularspacing member and secured to the assembly by the adhesive coating onsaid protective sheet, with said last-mentioned pad disposed inopposition to the gel-supporting pad of the electrode structure.

16. A method of fabricating a disposable electrode and protective coverassembly therefor, comprising the steps of forming an opening, in anelongated strip of adhesively coated sheet material, defining thecentral portion of the electrode, mounting an adhesively coated secondsheet of relatively impermeable material across said opening utilizingtherefor, the adhesive on said second sheet, mounting and electricalterminal on said second sheet, which terminal includes a contactdisposed at the adhesively coated face thereof and substantiallycentered in said opening, applying a protective sheet, having an openingformed therein, of a size approximately that of-said first opening, tothe adhesive surface of said strip with such opening in aligned relationwith the opening in'said strip, mounting a pad, greater in size thansaid contact portion, to said second sheet by means of the adhesivethereon with said pad in superimposed relation on said portion, said padbeing less in size than the opening in said strip whereby an annularlyshaped area of the adhesive on said second sheet remains exposed,applying to such assembled structure a ring-like member having an innerperipheral size greater than that of said pad and less than that of theopening in said strip with said spacing member encircling said pad andengaged with the adhesive of the second sheet, applying a conductivematerial to said pad, covering said spacing member with an adhesivelycoated sheet of relatively impermeable material having a peripheral sizegreater than the outer periphery of spacing member and less than that ofthe outer periphery of said protective sheet, securing said cover sheetby means of the adhesive thereon to said spacing member and theprotective sheet, thereby sealing the pad and conductive materialthereon in the chamber defined by said spacing member and said secondand cover sheets, and severing the assembled electrode and protectedcover assembled from said elongated strip.

17. A method according to claim 16 comprising the additional step ofcutting said protective sheet, prior to its engagement with said firstsheet, along a generally radial line extending from the opening thereinto the peripheral edge of such sheet.

18. A method according to claim 16, comprising the additional step ofapplying to the outer face of said cover sheet, prior to the severanceof the structure from said elongated strip, a piece of abrading-typecleaning material having an adhesive coating on the face thereof appliedto said cover sheet by means of which said cleaning material is securedthereto.

19. A method according to claim 16 wherein the step of mounting saidelectrical terminal to said second sheet is effected prior to themounting of the latter on said strip.

20. A method according to claim 16 wherein the step of mounting saidelectrical terminal to said second sheet is effected following mountingof the latter on said strip.

21. A disposable type electrode for operatively connecting electricalequipment to the surface of live skin of a patient, comprising arelatively large sheet of relatively porous material having an adhesivecoating on one face thereof adapted to adhere to such a skin surface, asecond relatively small sheet of relatively impermeable materialcentrally disposed with respect to said first sheet and secured theretowith the peripheral edges of the second sheet spaced inwardly from theperipheral edges of the first sheet, said second sheet having anadhesive coating on the face thereof corresponding to the adhesivelycoated face of said first sheet, said sheets being retained in assembledrelation by the adhesive of one of said sheets engaged with the adjacentface of the other of said sheets, and with the central portion of theadhesively coated face of said second sheet being exposed, an electricalterminal extending through the exposed central portion of said secondsheet, said terminal having a contact portion disposed at the adhesivelycoated face thereof and means, ex tending outwardly from the other facethereof, arranged for effecting connection with an electrical conductor,the area of said adhesive coated face of said second sheet being greaterthan the area of said contact portion to provide an exposed areatherearound, a pad of porous material disposed at and engaged with saidcontact portion, said pad having an area greater than that of saidcontact portion and retained in operative position in engagementtherewith by the exposed adhesive coating of said second sheet, and aquantity of electrically conductive material contained on said pad,preapplied thereto and forming therewith a unitary part of theelectrode, operative to produce a conductive connection between saidcontact portion and live skin in contact with said pad when said firstsheet is applied to such live skin and retained in position by theadhesive coating of such sheet.

22. As an article of manufacture, a disposable type electrode foroperatively connecting electrical equipment to the surface of live skinof a patient, comprising a relatively large sheet of relatively porousmaterial having an adhesive coating on one face thereof adapted toadhere to such a skin surface, a second relatively small sheet ofrelatively impermeable material centrally disposed with respect to saidfirst sheet and secured thereto with the peripheral edges of the secondsheet spaced inwardly from the peripheral edges of the first sheet, saidsecond sheet having an adhesive coating on the face thereofcorresponding to the adhesively coated face of said first sheet, saidsheets being retained in assembled relation by the adhesive of one ofsaid sheets engaged with the adjacent face of the other of said sheets,and with the central portion of the adhesively coated face of saidsecond sheet being exposed, an electrical terminal extending through theexposed central portion of said second sheet, said terminal having acontact portion disposed at the adhesively coated face thereof andmeans, extending outwardly from the other face thereof, arranged foreffecting connection with an electrical conductor, the area of saidadhesive coated face of said second sheet being greater than the area ofsaid contact to provide an exposed area therearound, a pad of porousmaterial disposed at and engaged with said contact portion, said padhaving an area greater than that of said contact portion and retained inoperative position in engagement therewith by the exposed adhesivecoating of said second sheet, and a quantity of electrically conductivematerial contained on said pad, preapplied thereto and forming therewitha unitary part of the electrode, operative to produce a conductiveconnection between said contact portion and live skin in contact withsaid pad when said first sheet is applied to such live skin and retainedin position by the adhesive coating of such sheet, and a protectivecover structure for said pad and exposed adhesive of said first sheet,of a size to extend across and engage said adhesive of the first sheet,the adhesive engaged surface of said cover structure being such that thelatter may be easily stripped from such adhesive, said cover structure,covering said pad, outwardly from peripheral portions of said coverstructure, forming a recess at the inner side thereof, into which saidpad ex tends.

23. An article of manufacture according to claim 22, wherein the outerperiphery of the exposed area of the adhesively coated face of saidsecond sheet is of a size to overlie and adhesively engage the adjacentportion of said cover structure and form a seal therebetween whereby thepad and preapplied conductive gel are thereby sealed between said secondsheet and said cover structure.

24. A method of fabricating a disposable electrode and protective coverassembly therefor, comprising the steps of disposing on an elongatedstrip of adhesively coated sheet material, a relatively small adhesivelycoated second sheet of relatively impermeable material with theadhesively coated faces of said first and second sheets beingcorrespondingly oriented and with second sheet being secured to saidfirst sheet by the adhesive on one of said sheets, and with the centralportion of the adhesively coated face of said relatively smaller secondsheet being exposed, mounting an electrical terminal on said secondsheet, which terminal includes a contact portion disposed atand less insize than the exposed adhesively coated face of said second sheetsubstantially centered thereon whereby said exposed face forms anannularly shaped adhesive coated area therearound, applying a protectivesheet, having an opening formed therein of a size approximately that ofthe exposed adhesively coated face of said second sheet, to the adhesivesurface of said strip with such opening in aligned relation with saidexposed adhesively coated face of said second sheet, mounting a pad,greater in size that said contact portion, to said second sheet by meansof the adhesive thereon, with said pad in superimposed relation on saidportion, said pad being less in size than the exposed adhesively coatedface of said second sheet whereby an annularly shaped area of adhesiveon said second sheet remains exposed, applying a conductive material tosaid pad, covering said pad with a cover structure of relativelyimpermeable material having a peripheral size greater than the outerperiphery of the exposed adhesively coated face of said second sheet andhaving an outwardly extending cen tral portion of a size to enclose saidpad securing the adjacent peripheral portions of said outwardlyextending portion to said second sheet by means of the exposed adhesivethereon, thereby sealing the pad and conductive material thereon in thechamber defined by the outwardly extending portion of said coverstructure and said second sheet, and severing the assembled electrodeand protective cover structure from said elongated strip.

Disclaimer and Dedication 3,805,769.R0bert W. Sessions, Hinsdale, Ill.DISPOSABLE ELECTRODE. Pa-

tent dated Apr. 23, 1974. Disclaimer and Dedication filed Feb. 4, 1981,by the assignee, Minnesota Mining & Manufacturing Co. Hereby disclaimsand dedicates to the Public the remaining term of said patent.

[Oflicial Gazette October 25, 1983.]

1. A disposable type electrode for operatively connecting electricalequipment to the surface of live skin of a patient, comprising a sheetof relatively porous material having an adhesive coating on one facethereof adapted to adhere to such a skin surface, said sheet having anopening therein, a second sheet of relatively impermeable materialcompletely spanning the area of said opening, said second sheet havingan adhesive coating on the adjacent face thereof contacting said firstsheet for retaining the same in assembled relation an electricalterminal extending-through and secured to said second sheet on a portionthereof extending across the opening in said first sheet, said terminalhaving means at the outer side of said second sheet for effectingconnection with an electrical conductor, and having a contact portiondisposed in the opening said first sheet, the area of said opening beinggreater than the area of said contact portion to provide an annular areatherearound at which the adhesive coating of said second sheet isexposed, a pad of porous material disposed at the opening in said firstsheet and engaged with said contact portion, said pad having an areagreater than that of said contact portion and retained in operativeposition in engagement therewith by the exposed adhesive coating of saidsecond sheet, and a quantity of electrically conductive materialcontained on said pad, preapplied thereto and forming therewith aunitary part of the electrode, operative to produce a conductiveconnection between said connector and live skin in contact with said padwhen said first sheet is applied to such live skin and retained inposition by the adhesive coating of such sheet. on a portion thereofextending across the opening in said first sheet, said terminal havingmeans at the outer side of said second sheet for effecting connectionwith an electrical conductor, and having a contact portion disposed inthe opening said first sheet, the area of said opening being greaterthan the area of said contact portion to provide an annular areatherearound at which the adhesive coating of said second sheet isexposed, a pad of porous material disposed at the opening in said firstsheet and engaged with said contact portion, said pad having an areagreater than that of said contact portion and retained in operativeposition in engagement therewith by the exposed adhesive coating of saidsecond sheet, and a quantity of electrically conductive materialcontained on said pad, preapplied thereto and forming therewith aunitary part of the electrode, operative to produce a conductiveconnection between said connector and live skin in contact with said padwhen said first sheet is applied to such live skin and retained inposition by the adhesive coating of such sheet.
 2. An electrodeaccording to claim 1, wherein the dimensions of the opening in saidfirst sheet of the electrode structure are greater than thecorresponding outer dimensions of said pad to provide an annular spacebetween said pad and first sheet at which the adhesive coating on saidsecond sheet is exposed, and closure means in sealing engagement withsaid second sheet.
 3. An electrode according to claim 1 wherein saidpad, respective sheets and the opening in said first sheet arerespectively circular in configuration, with the respective componentsand said terminal being disposed on a common axis.
 4. An electrodeaccording to claim 1, wherein said electrical terminal comprises anouter connector member and an inner contact member engaged therewith,each of which is provided with a base portion in contact with theadjacent face of said second sheet, that of the inner member being inengagement with the adhesive coating on said second sheet, said innermember extending through said second sheet and engaging said outermember with said second sheet clamped between said base portions.
 5. Asan article of manufacture, a disposable type electrode for operativelyconnecting electrical equipment to tHe surface of live skin of apatient, comprising a sheet of material having an adhesive coating onone face thereof adapted to adhere to such a skin surface, said sheethaving an opening therein, a second sheet of material completelyspanning the area of said opening with its peripheral portionsadhesively secured to said first sheet to retain the same in assembledrelation, an electrical terminal extending through and secured to saidsecond sheet on a portion thereof extending across the opening in saidfirst sheet, said terminal having means at the outer side of secondsheet for effecting connection with an electrical conductor, and havinga contact portion, disposed in the opening in said first sheet, a pad ofporous material disposed at the opening in said first sheet and engagedwith the adjacent contact portion, said pad being retained in positionby adhesive surrounding said adjacent contact portion, a quantity ofelectrically conductive material contained on said pad operative toproduce a conductive connection between said connector and live skin incontact with said pad when said first sheet is applied to such live skinand retained in position by the adhesive coating of said sheet, and aprotective cover structure for said pad and exposed adhesive of saidfirst sheet, of a size to extend across and engage said adhesive of thefirst sheet, the adhesive-engaged surface of said cover structure beingsuch that the latter may be easily stripped from such adhesive, saidcover structure having means for spacing the portion of said coverstructure covering said pad, outwardly from peripheral portions of saidcover structure, forming a recess at the inner side thereof, into whichsaid pad extends.
 6. An article of manufacture according to claim 5,wherein said cover structure comprises a protective sheet engaged withthe adhesive of the said first sheet, and having an opening thereingreater in size than said pad, an annular spacing member encircling theopening in such sheet and having an internal size greater than that ofsaid pad and an external size greater than the opening in suchprotective sheet, and a cover sheet greater in size than said spacingmember overlying the latter and having a coating of adhesive on theadjacent face in engagement with said spacing member, the peripheraledges of said cover sheet extending laterally outward from said spacingmember and in adhesive engagement with the outer face of the adjacentsheet of said cover member.
 7. An article of manufacture according toclaim 6, wherein said sheet of the cover assembly contacting theadhesive of said first sheet is provided with a cut therein extendingfrom the opening therein to the periphery thereof for facilitatingstripping of such sheet from said first sheet and thereby the coverassembly from the electrode structure.
 8. An article of manufactureaccording to claim 7, wherein the surface of said sheet of the coverassembly contacting the adhesive of said first sheet is provided with acoating of a material which will permit relatively easy stripping ofsaid sheet from the first sheet.
 9. An article of manufacture accordingto claim 8, wherein said surface coating comprises a siliconecomposition.
 10. An article of manufacture according to claim 7, whereinsaid pad, spacing member, respective sheets and the openings therein arerespectively circular in configuration, with the respective componentsand said terminal being disposed on a common axis.
 11. An article ofmanufacture according to claim 6, wherein the dimensions of therespective openings in said first sheet of the electrode structure andsaid protective sheet are greater than the corresponding innerdimensions of said spacing ring, whereby said pad and its contents aresealed by said ring, the second sheet of the electrode structure andsaid cover sheet of the cover assembly, said sheets being secured tosaid ring by the respective adhesive coatings.
 12. An article ofmanufacture according to claim 6, wherein saId electrical terminalcomprises an outer connector member and an inner contact member engagedtherewith, each of which is provided with a base portion in contact withthe adjacent face of said second sheet, that of the inner member beingin engagement with the adhesive coating on said second sheet, said innermember extending through said second sheet and engaging said outermember with said second sheet clamped between said base portions.
 13. Anarticle of manufacture according to claim 5, comprising a path ofmaterial secured to said cover assembly and having a relatively roughexterior surface which may be employed to roughen the skin surface ofthe patient at the point of application of the electrode thereto.
 14. Anarticle of manufacture according to claim 13, wherein said patchcomprises a strip of adhesive backed synthetic rubber or the likeadhesively secured to said cover assembly.
 15. An article of manufactureaccording to claim 5, wherein said cover assembly is provided with aporous pad disposed within said annular spacing member and secured tothe assembly by the adhesive coating on said protective sheet, with saidlast-mentioned pad disposed in opposition to the gel-supporting pad ofthe electrode structure.
 16. A method of fabricating a disposableelectrode and protective cover assembly therefor, comprising the stepsof forming an opening, in an elongated strip of adhesively coated sheetmaterial, defining the central portion of the electrode, mounting anadhesively coated second sheet of relatively impermeable material acrosssaid opening utilizing therefor, the adhesive on said second sheet,mounting and electrical terminal on said second sheet, which terminalincludes a contact disposed at the adhesively coated face thereof andsubstantially centered in said opening, applying a protective sheet,having an opening formed therein, of a size approximately that of saidfirst opening, to the adhesive surface of said strip with such openingin aligned relation with the opening in said strip, mounting a pad,greater in size than said contact portion, to said second sheet by meansof the adhesive thereon with said pad in superimposed relation on saidportion, said pad being less in size than the opening in said stripwhereby an annularly shaped area of the adhesive on said second sheetremains exposed, applying to such assembled structure a ring-like memberhaving an inner peripheral size greater than that of said pad and lessthan that of the opening in said strip with said spacing memberencircling said pad and engaged with the adhesive of the second sheet,applying a conductive material to said pad, covering said spacing memberwith an adhesively coated sheet of relatively impermeable materialhaving a peripheral size greater than the outer periphery of spacingmember and less than that of the outer periphery of said protectivesheet, securing said cover sheet by means of the adhesive thereon tosaid spacing member and the protective sheet, thereby sealing the padand conductive material thereon in the chamber defined by said spacingmember and said second and cover sheets, and severing the assembledelectrode and protected cover assembled from said elongated strip.
 17. Amethod according to claim 16 comprising the additional step of cuttingsaid protective sheet, prior to its engagement with said first sheet,along a generally radial line extending from the opening therein to theperipheral edge of such sheet.
 18. A method according to claim 16,comprising the additional step of applying to the outer face of saidcover sheet, prior to the severance of the structure from said elongatedstrip, a piece of abrading-type cleaning material having an adhesivecoating on the face thereof applied to said cover sheet by means ofwhich said cleaning material is secured thereto.
 19. A method accordingto claim 16 wherein the step of mounting said electrical terminal tosaid second sheet is effected prior to the mounting of the latter onsaid strip.
 20. A Method according to claim 16 wherein the step ofmounting said electrical terminal to said second sheet is effectedfollowing mounting of the latter on said strip.
 21. A disposable typeelectrode for operatively connecting electrical equipment to the surfaceof live skin of a patient, comprising a relatively large sheet ofrelatively porous material having an adhesive coating on one facethereof adapted to adhere to such a skin surface, a second relativelysmall sheet of relatively impermeable material centrally disposed withrespect to said first sheet and secured thereto with the peripheraledges of the second sheet spaced inwardly from the peripheral edges ofthe first sheet, said second sheet having an adhesive coating on theface thereof corresponding to the adhesively coated face of said firstsheet, said sheets being retained in assembled relation by the adhesiveof one of said sheets engaged with the adjacent face of the other ofsaid sheets, and with the central portion of the adhesively coated faceof said second sheet being exposed, an electrical terminal extendingthrough the exposed central portion of said second sheet, said terminalhaving a contact portion disposed at the adhesively coated face thereofand means, extending outwardly from the other face thereof, arranged foreffecting connection with an electrical conductor, the area of saidadhesive coated face of said second sheet being greater than the area ofsaid contact portion to provide an exposed area therearound, a pad ofporous material disposed at and engaged with said contact portion, saidpad having an area greater than that of said contact portion andretained in operative position in engagement therewith by the exposedadhesive coating of said second sheet, and a quantity of electricallyconductive material contained on said pad, preapplied thereto andforming therewith a unitary part of the electrode, operative to producea conductive connection between said contact portion and live skin incontact with said pad when said first sheet is applied to such live skinand retained in position by the adhesive coating of such sheet.
 22. Asan article of manufacture, a disposable type electrode for operativelyconnecting electrical equipment to the surface of live skin of apatient, comprising a relatively large sheet of relatively porousmaterial having an adhesive coating on one face thereof adapted toadhere to such a skin surface, a second relatively small sheet ofrelatively impermeable material centrally disposed with respect to saidfirst sheet and secured thereto with the peripheral edges of the secondsheet spaced inwardly from the peripheral edges of the first sheet, saidsecond sheet having an adhesive coating on the face thereofcorresponding to the adhesively coated face of said first sheet, saidsheets being retained in assembled relation by the adhesive of one ofsaid sheets engaged with the adjacent face of the other of said sheets,and with the central portion of the adhesively coated face of saidsecond sheet being exposed, an electrical terminal extending through theexposed central portion of said second sheet, said terminal having acontact portion disposed at the adhesively coated face thereof andmeans, extending outwardly from the other face thereof, arranged foreffecting connection with an electrical conductor, the area of saidadhesive coated face of said second sheet being greater than the area ofsaid contact to provide an exposed area therearound, a pad of porousmaterial disposed at and engaged with said contact portion, said padhaving an area greater than that of said contact portion and retained inoperative position in engagement therewith by the exposed adhesivecoating of said second sheet, and a quantity of electrically conductivematerial contained on said pad, preapplied thereto and forming therewitha unitary part of the electrode, operative to produce a conductiveconnection between said contact portion and live skin in contact withsaid pad when said first sheet is applied to such live skin and retainedin position by the adhesive coating of such sheet, and a protectivecover structure for said pad and exposed adhesive of said first sheet,of a size to extend across and engage said adhesive of the first sheet,the adhesive engaged surface of said cover structure being such that thelatter may be easily stripped from such adhesive, said cover structure,covering said pad, outwardly from peripheral portions of said coverstructure, forming a recess at the inner side thereof, into which saidpad extends.
 23. An article of manufacture according to claim 22,wherein the outer periphery of the exposed area of the adhesively coatedface of said second sheet is of a size to overlie and adhesively engagethe adjacent portion of said cover structure and form a sealtherebetween whereby the pad and preapplied conductive gel are therebysealed between said second sheet and said cover structure.
 24. A methodof fabricating a disposable electrode and protective cover assemblytherefor, comprising the steps of disposing on an elongated strip ofadhesively coated sheet material, a relatively small adhesively coatedsecond sheet of relatively impermeable material with the adhesivelycoated faces of said first and second sheets being correspondinglyoriented and with second sheet being secured to said first sheet by theadhesive on one of said sheets, and with the central portion of theadhesively coated face of said relatively smaller second sheet beingexposed, mounting an electrical terminal on said second sheet, whichterminal includes a contact portion disposed at and less in size thanthe exposed adhesively coated face of said second sheet substantiallycentered thereon whereby said exposed face forms an annularly shapedadhesive coated area therearound, applying a protective sheet, having anopening formed therein of a size approximately that of the exposedadhesively coated face of said second sheet, to the adhesive surface ofsaid strip with such opening in aligned relation with said exposedadhesively coated face of said second sheet, mounting a pad, greater insize that said contact portion, to said second sheet by means of theadhesive thereon, with said pad in superimposed relation on saidportion, said pad being less in size than the exposed adhesively coatedface of said second sheet whereby an annularly shaped area of adhesiveon said second sheet remains exposed, applying a conductive material tosaid pad, covering said pad with a cover structure of relativelyimpermeable material having a peripheral size greater than the outerperiphery of the exposed adhesively coated face of said second sheet andhaving an outwardly extending central portion of a size to enclose saidpad securing the adjacent peripheral portions of said outwardlyextending portion to said second sheet by means of the exposed adhesivethereon, thereby sealing the pad and conductive material thereon in thechamber defined by the outwardly extending portion of said coverstructure and said second sheet, and severing the assembled electrodeand protective cover structure from said elongated strip.